我制作了一个连接到SQLite的应用程序。它应该存储供应商ID和名称，并具有用于在数据库中添加，更新，删除，清除，退出，显示和搜索条目的按钮。但是，更新和删除根本不起作用，并且出现如下错误：'NoneType'对象没有属性'delete'。我在哪里和想念什么？为什么更新和删除按钮不起作用？
from tkinter import*
import tkinter.messagebox
import venddatabase
class Vendor(tkinter.Frame):
def __init__(self,root):
self.root = root
super(Vendor, self).__init__()
self.root.title("vendor management")
self.root.geometry("1350x7500+0+0")
self.root.config(bg="white")
vendor_name = StringVar()
vendor_id = StringVar()
#===============================================Frames=================================
def iEXIT():
iEXIT=tkinter.messagebox.askyesno("vendor management","confirm if you want to exit")
if iEXIT>0:
root.destroy()
return
def addData():
if(len(vendor_id.get())!=0):
venddatabase.addvendor(vendor_id.get(),vendor_name.get())
vendorlist.delete(0,END)
vendorlist.insert(END,(vendor_id.get(),vendor_name.get()))
def DisplayData():
vendorlist.delete(0, END)
for row in venddatabase.viewData():
vendorlist.insert(END, row, str(""))
def vendRec(event):
global vd
if vendorlist.curselection():
index = vendorlist.curselection()
if index:
vd=vendorlist.get(index[0])
self.lblvend.delete(0, END)
self.lblvend.insert(END,vd[1])
self.lblvends.delete(0, END)
self.lblvends.insert(END, vd[1])
#searchVend = vendorlist.curselection()[0]
#vd = vendorlist.get(searchVend)
#self.lblvend.insert(END, vd[1])
#self.lblvends.delete(0, END)
#self.lblvends.insert(END, vd[2])
def deleteData():
#if(len(vendor_id.get())!=0):
venddatabase.deleteRec(vendor_id)
clearData()
DisplayData()
def clearData():
vendorlist.delete(0,END)
def searchDatabase():
vendorlist.delete(0,END)
for row in venddatabase.searchData(vendor_id.get(),vendor_name.get()):
vendorlist.insert(END,row,str(""))
def Update():
if(len(vendor_id.get())!= 0):
#venddatabase.deleteRec(vd[0])
venddatabase.dataUpdate(vendor_id.get(),vendor_name.get())
#vendorlist.delete(0,END)
#vendorlist.insert(END,(vendor_id.get(),vendor_name.get()))
MainFrame = Frame(self.root,bg="white")
MainFrame.grid()
titleFrame = Frame(MainFrame,bd=2,padx=20,pady=8, bg="Ghost white",relief=RIDGE)
titleFrame.pack(side=TOP)
self.lbltitle=Label(titleFrame,font=('arial',30,'bold'),text="VENDOR MANAGEMEMT",bg="Ghost White")
self.lbltitle.grid()
buttonf=Frame(MainFrame,bd=2,width=90,height=50,padx=18,pady=20,bg="Ghost White",relief=RIDGE).place(x=8,y=600)
dataf = Frame(MainFrame, bd=1, width=1900, height=300, padx=20, pady=20, bg="Cadet blue", relief=RIDGE)
dataf.pack(side=BOTTOM)
datafl = LabelFrame(MainFrame, bd=1, width=500, height=360, padx=2,pady=3,font=('arial',20,'bold'),text="vendor info",bg="Ghost White", relief=RIDGE)
datafl.pack(side=LEFT)
datafr = LabelFrame(MainFrame, bd=1, width=450, height=330, padx=7,pady=3,bg="Ghost White", relief=RIDGE,font=('arial',20,'bold'),text="vendor details").place(x=1000,y=100)
self.lblvend = Label(datafl, font=('arial', 15, 'bold'), text="vendor id", bg="Ghost White").place(x=0,y=50)
self.lblvend = Entry(datafl, font=('arial', 20, 'bold'), textvariable= vendor_id,width=20).place(x=130,y=50)
self.lblvends = Label(datafl, font=('arial', 15, 'bold'), text="vendor name", bg="Ghost White").place(x=0, y=200)
self.lblvends = Entry(datafl, font=('arial', 20, 'bold'), textvariable=vendor_name, width=20).place(x=130, y=200)
scrollbar=Scrollbar(datafr)
scrollbar.grid(row=0,column=1,sticky='ns')
vendorlist=Listbox(datafr,width=41,height=16,font=('arial',12,'bold'), yscrollcommand=scrollbar.set)
vendorlist.bind('<<ListboxSelect>>',vendRec)
vendorlist.grid(row=0,column=0)
scrollbar.config(command=vendorlist.yview)
self.btnaddvendor=Button(buttonf,text="Add new",font=('arial',12,'bold'),height=3,width=10,bd=2,command=addData,bg="Ghost White").place(x=8,y=600)
self.upvendor = Button(buttonf, text="update", font=('arial', 12, 'bold'), height=3, width=10, bd=2,command=Update,bg="Ghost White").place(x=150,y=600)
self.disvendor = Button(buttonf, text="display", font=('arial', 12, 'bold'), height=3, width=10, bd=2,command=DisplayData,bg="Ghost White").place(x=400, y=600)
self.exvendor = Button(buttonf, text="search", font=('arial', 12, 'bold'), height=3, width=10, bd=2,command=searchDatabase,bg="Ghost White").place(x=600, y=600)
self.clearvendor = Button(buttonf, text="clear", font=('arial', 12, 'bold'), height=3, width=10, bd=2,
command=clearData, bg="Ghost White").place(x=700, y=600)
self.deletevendor = Button(buttonf, text="delete", font=('arial', 12, 'bold'), height=3, width=10, bd=2,
command=deleteData, bg="Ghost White").place(x=850, y=600)
self.searchvendor = Button(buttonf, text="exit", font=('arial', 12, 'bold'), height=3, width=10, bd=2,
command=iEXIT, bg="Ghost White").place(x=950, y=600)
if __name__ == '__main__':
root= tkinter.Tk()
application = Vendor(root)
root.mainloop()